Transmission control



Filed Sept. 17, 1932 4 Sheets-Sheet 1 Jah 25, 1937 P. l..` TENNEY ET AL 2,068,716

TRANSMISSION CONTROL Jan. 26, 1937- P. l.. TENNEY ET AL 2,068,716

TRANSMISS ION CONTROL zzz im I l Illll ilw .M {I4/alim 2 Wl Y K gyWe/wfw /d/ @inlay/wg @yf 75,1%

Jan. 26, 1937. P. l.. TENNEY ET AL 2,068,716

TRANSMIS S ION CONTROL Filed Sept. 17, 1932 4 Sheets-Sheet 4,

9! 7l 55,43 I Q99 Mf/Mg 'Patented Jaa. 2s, 1937 ,TRANSMIS SION CONTROL i Perry L. Tenney andA Olaf Rasmussen, Lansing,

Mich., assignors to General Motors Corporaxtlon, Detroit, Mich., a corporation oi Delaware Application September 17, 1932, Serial No. 633,615

`1'1 Claims.

This invention-relates to control mechanism for power transmission, and may be described as a senil-automatic control for a vehicular change speed transmission.

Anobject of the invention is to simplify the (ci. 19g-.01)

In the header 23` communicating with the manifold I3 is a throttle valve controlled by an external leverV 26. On the iloor board 21 of the car is an accelerator pedal 28 pivoted at 3|. This 5 pedal is connected by a rod 33 to one arm 85 oi a 5 control of. the ratio changes provided by the three-arm lever 31.` A second arm 88 is contrans'misslon. nected by a link 4| to the throttle control lever Another object is to provide for progressive 25. A third arm 43 is connected by a link 46 to y ratio changes controlled preferably by the movea lever 41, the `Se0nl 81111 55 0f which level' 1S ment of the engine throttle-operating means. connected by a rod 5| to the end oi a valve plung- 10 Another object is to provide for sequential er 53 operable ln Cylinder 55 0f Valve body deS- clutch releasing and progressive gear shifting lgneted 8S n WhOle by numeral 51- A Spring 59 operations. holds the accelerator pedal in its released posi- Still another object is to provide for such an tiOn. automatic gear shifting arrangement as shall be Beneath the floor board is a lever 88 pivoted at 15 adapted to Vpermit any desired manual shifting 6l- This lever has en erm extending through the at any time. floor and terrriinating in a. button 88. The lever A stili further object relates to the association is held in its released position by a spring 61. A .of a free wheeling device with an automatic gear rociv `69 connects this lever with a plunger 1| shifting control, the arrangement being such that Operable in a Cylinder bore 73 8.150 Infl-ned in 20 Vthe automatic gear shifting control 'is rendered valve member 51.

inoperative whenever the free wheeling device is Between the tubular pnSSaSeS 55 and 13 1S a inoperative. third parallel passage 15. In this passage moves Other objects will-be understood from the fola third plunger 15 A eOver 11 4310668 the Open lowing description. ends of the three passages and is provided with 25 In the drawingsone or more suitable openings such as 18 com- Fig. 1 is a View in elevation of an engine and mnnleatlng .with the Outer ein Each Valve the transmission of a; motor vehicle having the plunger hS en annular groove Il (Fig. 9), a novel control associated therewith. tubular bore 83 and, extending from the bore. a

Fig. 2 is a top plan view of the change speed radial passage 85. In the outer wall oi the valve 30 and free wheeling units. body is an opening 81 communicating with pas- Fig. 3 is a similar view, partly broken away and sage 65. From this opening 81 a pipe 89 extends with some of the control mechanism removed. t0 the intake manifold Diemetrlcally ODDOSilSe Fig. 4 is a section on line 4-4 of Fig, 3. opening 81 is an opening 8| communicating with Fig. 5 is a transverse section through the free passage 73- In the Wells between the Several 35 wheel unit. bores are apertures 83 and 83', which apertures, Fig. 6 is a perspective of the control mechanism are in alignment with openings 81 and 9|. A pipe detached. 95 connects the opening 9| with a power cylin-` Fig. '1 is a plan view of the control mechanism der 81 suitably supported as at 99.

40 with the parts in low speed position. VWithin the power cylinder ls a piston |80 hav- 40 Fig. 8 is a. plan view of the control with the ing a rod |0| which connects to a lever arm |08 parts in second speed position. extending from a spindle |05 to which spindle are Fig. 9 is a transverse section through the valve also connected other arms |01 and |08. A rod member, A is connected to arm |01. At its other end Fig. 10 shows a modification diagrammatically. rod engages a bracket arm Il! beyond which 45 Referring by reference characters to the drawit is forked to straddle the bracket. Bracket H5 ings, the engine of the vehicle is represented by is pivoted to the clutch pedal as shown at IIC. numeral It has an intake manifold i8. At The forked ends of rod are slotted as at ||1 I5 is the housing for the change speed transmisthrough which slots extend the spindle end of a sion, and to the rear oi this housing is another, conventional clutch throw-out lever Ill. The 50 I1, containing an overrunning clutch constitutend 0i the throw-out lever is held, by a spring ing a freewhefel unit. At I8 is the housing for H9, in contact with the bracket IIB. A screw the clutch between the engine crankshaitand |2| is adjustably held in bracket Il! and engages the transmissiom The clutch is to'be'bperated the hub l|23 oi the clutch pedal 2|. By these by a substantially conventional pedal 2|.` expedients the clutch may be released by pressure 55 on the pedal or by a push through rod A rod |25 is connected by a suitable resilient ellement |21 to arm |09. The rod |25 is operable to shift the transmission ratios in a way to be described below.

On the instrument panel is a button |21 for controlling a free wheel lock-out jaw clutch.

From the button a rod |29 extends through the dash |3| and is connected to a lever |33 pivoted on the front side of the dash. From lever |33 a rod |35 extends to a second lever |31. A rod |39 connects this second lever to the intermediate valve plunger 16. Also, from the second lever extends a rod |4| to a bell crank lever |43. From the second arm of the bell crank levera rod |45 extends to and is connected with an arm |41 (Figs. 2 a-n d 5) carried by a. spindle |49 rotatably mounted in the top` of housing I1. `Within the housing I1 the spindle |49 is provided with a forked arm |5I, the furcations of which straddle the upturned end of an angle plate |53,` the other .end of which angle plate is connected by a pin |55 to a fork |51-whereby the rocking of spindle |49 may reciprocate the fork |51. The ends |59 of fork |51 engage in a channel |6| (Fig. 3) of a sliding sleeve |63.A The sleeve |63 is in slidable but non-rotating relation with an inner end ofthe driven shaft |65, there being splines as at |61 to provide for the connection.-

Slidably splined' on the output shaft of the change speed transmission is an inner hub' |1I and between this inner hub and the outer sleeve |63 is a substantially conventional overrunning vclutch |13. In addition to its spline connection with sleeve |63, shaft |65 has internal clutchv teeth |15 adapted to be engaged by external teeth |11 on hub |1| when the hub and sleeve are reciprocated together toward the rear bythe fork |51.

The W speed and reverse shift rail '|19 extends from the change speed housing I5 into the free wheel housing I1 and reciprocates through the fork |51 as clearly shown in Fig.` 5. 'This shift rail |19 has a shoulder I8| to engage a pin |83 extending through the horizontal arm of the angle plate |53 and partlythrough the fork member |51 so that the rearward reciprocation of the reverse rail |19 manipulates the free wheel lock-out jaw clutch in a manner which will be obviousfrom aninspection of Fig. 3 and Fig. 5.

At |85 is a lever pivoted on the top of the housing I1. This lever has a lug |81 engaging a part |89 on lever |41 to prevent the shifting of the lock-out device. Before shifting the fork |51, lever |85 must be rocked to remove lug |81 from the path of movement of the part |89. Rocking of lever |85 is performed by the clutch releasing action. To permit the clutch to so function a rod |9| is connected to an arm of lever |85 and to the clutch pedal 2|.` v

The change speed gearing is not of itself new' and is not fully illustrated. It may be sufficient to explain that a spline shaft 20| is movable axially to be clutched to the drivingshaft or to a driven gear to provide direct or high speed in one position of adjustment and to provide second speed in another position of adjustment. Preferably associated vwith the jaw clutches are frictional clutches to be first engaged, Vwhereby synchronization is accomplished before the engagement of the jaw teeth. These shifts are made by a fork 203 (see Fig. 4) carried by the high speed shift rail 205. The low and reverse shift rail |19, referred to above, carries a fork manual operation of the shift lever 2|9.

201 only partially shown. This low speed fork shifts a gear 209 slidably splined on shaft 20| to effect gear engagement for producing low speed and reverse drive in its positions of adjustment.'

On the top of each fork is a groove, such a groove 2|I being shown on fork 201 on Fig. 4, These grooves or channels receive the ends of a lever 2|3. If one end of the lever be anchored, force applied longitudinally to the lever will move the unanchored end about the anchored end as a fulcrum. The fork associated with the unanchored end is thereby moved longitudinally for making gear shifts. Provision is made to anchor either end as may be. desired in order to make the required shifts. An interlocking plate 2|5 is bowed upwardly at its mid portion and downwardly at` each end. Its mid portion has ra slot 2|1 for the passage of the shift lever 2|9 during the longitudinal movement of the latter. Pins 22|, 22|' on the ends of lever 2|3 extend into slots 223, 223" at the ends of the interlocking plate. This plate is guided for transverse movement only by pins 225 and 221 extending downwardly'from the cover plate'229 and entering slots 23| and y223 respectively at thecorre.

22|' and that end of lever 2|3 becomes. a fulcrum. These transversemovements of the interlocking plate may be made by manual effort applied to the lever 2|9 vthe lower. end of lwhich engages the side walls of slot 2|1 in .theplate or may be made by automatically operable mechanism to be described below. When the movements are effected by the lever 2|9 (the lever moving the interlocking plate through pressureon the walls of slot 2 1) the one or the other end f of the lever 2|3 is fixed and thereafterr longitudinal movements of the shift lever 2|9 rock the lever 2 I3 about its fulcrum to make the shifts into the speed ratio positions as usual. v ,Y

'Ihe novel mechanism now to be described is operable -to make the shifts without resort to The spindle 231 is rotatably journaled in the cover 229 (see Fig. 4). Within the housing I5 the spindle is provided with a lever arm 239 having an angularlyfdisposed part 24| extending through an opening 243 in the interlocking plate 2|5. A stud 245 connects the angularly rdisposed part 24| and the lever 2|3. Thev lever 239 is also formed with a forkedend 241 underlying the arched part of the interlocking plate2|5 and engages the lower end of the shift lever 2|9. On the outside of the cover 229 a lever arm249 is secured to the spindle 231. Thisarm 249 extends toward the rear as shown in Fig. 2. Rocking of the spindle 231by thev rotationof arm 249 operates to rock the lever arm 239, and the latter through the instrumentality of the pin 245 rocks the lever 2I3` about its anchored end to make gear shifts. This operation,Y therefore, corresponds in function to the manually effected longitudinal movement of the gear 'shift lever 2|9. As a matter of factlthe vgear shift lever 2|9 is given its usual longitudinal movements at the same time -as a result'of the slotted end of the lever arm 239 engaging the` lower extremity of the shift lever. Another spindle 25| is also journaled in the cover 229. It has within the housing I5 an arm 253, its end engaging a pinV 255 on the interlocking plate 215. Outside the cover 229 the spindle 25| carries a rigid arm v251. Arm 251 is apertured as at 259, and in the aperture' is pivoted a lug 26| on a pin 263; the lug is heldin abutment with the end of the arm 251 by a spring 265. rocked by the rotation of the outer arm 251 the interlocking plate is shifted transversely. In so moving the interlocking plate, the shift lever 2|9 is similarly moved owing to its engagement in the slot 2I1. lIn the two positions of adjustment of the interlocking plate the one or the other of the endsof the lever 2| 3 is anchored as explained above.

The means to operate the lever arm 251 to shift plate 2|5 from a position adapted for vshifting either to low or reverse to a position for shifting to high and second speed and then to operate lever arm 249 to make the several clutch engagements for the speed ratios will next be def scribed. On an extension 261 of the cover of the free wheel housing I1 is a pivot 269 for a lever 21|, the end of which is engaged by the forked and slotted end 213 of rod |25. At its other end the lever 21| has a cam slot 215 to receive a pin 211 carried on one end of another lever 219, the latter pivoted at 26| to the same cover extension 261. A slider bar 283 is guided at one end by a pin 285 extending through 'a slot 281 in the bar. At its other end the slider bar is pivoted as at 28,9 to the lever 219. A rocker arm 29| has an intermediate fixed pivot pin 293. It has a downwardly directed pin 295 near one end pivotally` be described. Secured by fastening means 30| to the'slider bar 283 is a cam plate 303having a projecting face 305. Ihevslider bar 283 carries a spaced plate 301 secured-thereto. At 309 and 3| between the slider bar and the spaced plate are pivoted pawls 3|3v and 3|5. Each pawl has a grooved end 3|1 to engage a pin on the rocker arm 29|. Pivotally mounted as at 3|9 are pivoted bars 32| held apart by a springV 323. These bars engage the pawls and tend to hold them in the positionshown by Fig. 2 and Fig. 8. A spring 325 surrounds the pivot 269, is anchored to the parts 261 and the lever 21|, and functions to restore the slider bar 283 after it has been moved to effect gear shifting. The pivotal movement of .the pawls 3|3, 3|5 enables them to accommodate Athemselves to the movements of the pins 291 and 299 as the latter turn about the'center of rotation of the member 29| during the act of gear shifting. The bars 32| operate under the iniiuence of the spring 323 to normally hold the pawls in their retracted position. The pivotal mounting of the lug 26| is` to permit its being rotated against the tension of spring 265 by the retracting movement of the projection 305 whenever the lug 26| is in the path of movement of the projection 305 as it moves outwardly.

In Fig. 2, which shows the parts in neutral position, it will be seen that spring 323 acts on the bars 32| to yhold the pawls 3| 3 and 3|5 retracted. In this position of the lever 29| and the pawls, the pawls are so positioned that they will not engage the pins 291 and 299 if the slider bar 283 is reciprocated. It will be appreciated, however, that lever may be rocked about its pivot to such an angular position that one or the other of these pins is opposite the end of one of the When the lever arm 253 isf pawls. In Fig. 6 and Fig. 'I the lever has been rocked by manual operation sufllciently to bring pin 299 opposite the end of pawl 3|5. This is a low speed driving position. If now bar 283 is reciprocated, pawl 3|5 pushes on pin 299 and rocks lever 29| about its pivot 293. In so doing the pawl 3|5 must rock about its pivot 3|| to accommodate the arcuate movement of pin 299. However, pawl 3|3 remains retracted, and when the lever 29| is moving through its mid position the end of pawl 3|3 moves under pin 291 which,

thereafter, moves along-the outer wall of theV Vto the positionr shown by Fig. 8 a reverse movement of bar 283 brings it to the full line position of Fig. l8. Inso movingthe pawl 3|3 is rocked counterclockwise by the pin 291 and when the pawl 3|3 is free from the pin the spring 323 positions the pawl such that its grooved end is adjacent the pin 291 in a position to push the pin and rock the lever 29| upon the next forward movement of bar 283. Upon this next movement the end of pawl 3 l5 passes beneath pin 299 as the latter is moving toward the position shown by Fig. 7. Again, on the outward movement of bar 283 pawl 3|5 is actuated into a position such that its curved end is in a position to rock the lever. Briefly stated, the above described mechanism includes an operating member inthe form of a vacuum cylinder 91, the piston of which is moved (upwardly in the illustrated embodiment) under the influence of vacuum in the engine manifold. This movement of the piston operates to release the clutch and to make gear shifts to second and third speeds, then from third to second, from second to third, and so on progressively. After the completion of each shift the parts assume positions ready for the next shifting movement. It is very desirable that a free wheeling device should be associatedwith such an arrangement involving power operation of gear shifting acting progressively. This is especially important because, in its absence and in the event that a careless shift to second should be made when the car speed is high, too great a shock might be given the car and the passengers. To prevent this power operation of gear sluiting except when the free wheeling unit is in operation, the button |21, when pulled out to lock the free wheeling unit, simultaneously moves plunger 16 to the left and vents the power cylinder 91; as a result of which the automatic shifting mechanism is not available. Similar venting occurs when the free wheel device is locked out by a shift into reverse. The operation effected by the movement of the button should also be noted. In Fig. l the button is shown in the position when being held by pressure from the operators foot. This maintains the suction line avai1able.` When so held the vacuum cplinder is operable provided the free wheel unit is operableas explained above.`

The valve plunger 53 is actuated simultaneously with the throttle lever or accelerator pedal 29, When the latter is released the throttle is closed to idling position and the valve plunger 53 is pulled to the right so that the suction line is opened. If, at th'e same time, lthe second plunger is being held by the foot in the position illustrated, and if too the free wheeling unit is not locked out, the suction of the manifold is available to move piston |00. When in the operation of the car the accelerator pedal is released, the piston |00 moves up in the cylinder. Rod I|| releases the clutch and rod |25 operates slider-bar 283 forward. -When thereafter the in the connection 213 is provided to insure the y throttleis opened as by depressing the acceleral' vtor pedal, the power cylinder is vented, piston |00 moves down in the cylinder, and rod ||Il moves tothe left, whereupon the clutch reengages under theinilnence of its spring. Simultaneously rod |25. moves tothe right and spring 325 restores the slider bar to its initial position'l The cam slot- 215is so shaped that at the end of the gocking of lever 21|, lever 219 is reversely rocked,Jv thus withdrawing the operatingv pawl from the pin (291 or 299) onthe lock bar. The purpose of this featureof they construction is to so remove the automatically operated parts as to permit manualoperation of the change4 speed mechanism to any desired position at any time. At the beginning of the reverse movement. of lever 21| the cam slot functions to again push slider bar 283v forward, and'the bar then withdraws toits initial position .until again shifted by the action of the power cylinder.A The slot clutch release prior to the gear shifting movements. v

When vthe button 65 is released the vacuum cylinder is vented and the operationfof the car is conventional in every respect.

A further brief statement of. successive steps in the operation may help to make the action better understood. It will be assumed that the transmission is in neutral (Fig. 2) that the valves are as shown in Fig. 1; that the engine has just been started; and that the clutch is about to be disengaged by the vacuum power unit (the piston |00 moving upward). After the disengagement of the clutch by the power unit the rod ywill operator then manually shifts the lever 2|9 to its low speed position. .In so doing he first moves the lever 2|9 transversely, the knob end to the left. The lower end therefore moves to the right.

In so moving, the lower end moves in they slot 241 of the lever 239. This movement carries the interlockingy plate 2|5 transversely so that it Yerigages pin 22| on the high speed fork 203 whereby thisv end of the' lever 2|3 becomes its fulcrum.

The described movement of plate 2|5 rocks the lever 253 owing to the connecting pin 255. This action rocks the lever arm 251 swinging it to a e position wherein the lug 26| is in the path of movement of the projection 305 on the plate 303. The operator then moves the knob end of the lever toward the rear, the lower end moving for#` ward. As itdoes so, owing to its engagementy with the walls of slot 241, lever arm 239 is rocked with the result that the pin 245 is moved about pivot 231 as a center. In this Way the lever 2|3 is rocked about its fulcrum 22| and the transmission is shifted to low speed. In' so doing,'the arm 249.galso rotates about 231 as a center and, owing to its connection by means of pin 295 with the rocker 29|, `the latter turns about its pivot 293 and assumes the position shown by Fig. '7 which may be described as the low speed position. The car isfthen ready to be driven at low speed.

As theaccelerator pedal is depressed it pushes the plunger 53 into the cylinder bore of the I valve unit and vents the power cylinder, whereanism, owing to the presence of the slot .'214.

kThe spring v325 restores the slide bar v203, the `lug 26| rocking on its'pivot when engaged by projection 305 to permit the restoration of the slide bar to its neutral position.

When the speed of .the car has become such that ya shift to' second speed is' desired, the op-V erator releases the pressurev on the accelerator pedal. Vacuum is again established between the power` cylinder and the manifold. The clutch is withdrawn. After'the withdrawal of the clutch the rod |25 swings the levers 21| and 219. Lever'- 219 pushes the slider bar 283 forward. In vmoving it forward it rocks lever 29| lfrom the position shown by Fig. '1 toward the position shown in Fig. 8. This movementk rocks lever 249,'and the rmovement of 249 brings the lever 2|3`into its neutralposition (carrying the shift lever to its `neutral position at the same time).

At this point, and as the lever 29| is passing its mid position, the face 305 on plate 303 engages the lug 26| and rocks the lever arms 251 and 253 and shifts the interlocking plate transversely to a position where its opposite end is locked to the l, pin 22 on the low speed fork. As the movement of slide bar'283 continues, it'completes the rocking of lever 29| and rocks lever 2|3 about its opposite end and shifts the transmission to second speed. At the end of the shift the cam'slot separates the pawls from the pins and'thecar is ready for driving at second speed. Depression of the accelerator pedal then vents the power cylinder as before and permits reengagement of the clutch. The spring 325 causes a rst forward movement of the plate 283 and then a retracting movement so that the parts are ready for the following shift. Thereafter shifts to third speed and second speed occur progressively since the lever arm 251 is out of the path of movement of the cam plate 303. To again shift tolow speed or to shift into reverse, manual operationl of the shift lever 2|9 must be resorted to.` In the caser of shift to low, for example, release of the accelerator pedal vents the'power cylinder, releases the clutch, and moves the slider 283 forwardly. A manual shift to low moves the lever 251 to a position in the path of movement of projection 305 which is now in advance of the lug 26|. Depression of the accelerator pedal vents the power cylinder, engages the clutch, and withdraws rod |25. The spring 325 pulls back the slider, the

lug 26| turning on its pivot 263 against the action of spring 265 to permit thewithdrawal of the plate 283 to its release position from which it may again moveto shift `from low to second and high speeds as explained above.

Since the power cylinder may be Avented either by depressing the button 55 or by releasing theV accelerator pedal while the button` is depressed, it will be seen that for shifting'one may hold the buttony depressed and then release and depress the accelerator pedal, orv with the accelerator pedal released one may depress and release the button. y

It would be possible to make use of the automatic gear shifting mechanism in the absence of the vacuum control by merely connecting an equivalent of rod |25 directly to the clutch pedal, whereuponv clutch shifts would makethe gear changes substantially as provided in the above description. Such an arrangement is shown in Fig. 10 where rod |25 corresponds to rodr 25.

Other obvious changes may beA made within the scope of the invention. It should be mentioned also that when shifting into reverse (which is accomplished by manual operation only) the free wheel lock-out: device is necessarily made use of and as explained above this is associated with a venting of the power cylinder through the` movement of plunger'16 in precisely the same way as the power unit is vented when actuating the jaw clutch lock-out from the instrument panel button |21.

While the invention may obviously be used with any gear shifting mechanism, its use with change speed gearing employing synchronizing clutches provides for an improved operation.

We claim:

1. Ina motor vehicle having an engine, a main clutch, change speed mechanism, and a free wheel clutch the latter having a lock-out device, power means to release the main clutch and shift the change speed mechanism, and mechanism operating in response to the actuation of the lockout device to render the power means inoperative.

2. The invention defi-ned byclaim 1, said power means including a vacuum-operatedmotor and a communication between saidmotlor and a source of suction, said mechanism comprising a valve operative to vent the line of communication between the motor and thesource of suction.

3. The invention defined by claim 1 together with a' plurality of means to actuate said lock-out device, one of said means being manually operative and the other being responsive to a movenient ofthe change speed mechanism into its reverse driving position.

4. In a motor vehicle, an engine provided with a throttle valve and a control member therefor, a clutch, a pedal to operate the clutch, a change speed mechanism and a free wheeling clutch, the latter having a lock-out device, power means to release the clutch and to shift the change speed mechanism, said power means including a vacnum-.operated motor, a communication thereto from a source of suction, serially arranged valves in said communication, each valve designed to vent the suction line in one position of adjustment and to renderfthe suction line operable in a second position of adjustment, one valve operative in response to movements of the throttle control member, another in response to the lock-out device, and a manually operable member for the third valve.

5. In a motor vehicle, an engine having a source of suction, a fluid motor including a unitary movable member, a conduit from said'source of suction to said fluid motor whereby the unbalanced pressure is operable upon said movable member to move the same, a clutch, a change speed mechanism, mechanical connections between said movable member and said clutch and change speed mechanismV operable first to release the clutch and thereafter to shift the change speed mechanism. Y

6. In a motor vehicle, an engine having a Y y source of suction, a fluid motor including a unitary movable member, a conduit from said source of change speed mechanism including a high speed shift element, manually operable means for said change speed mechanism, power-operated means to shift said high speed shift element, said poweroperated means including mechanism to make a nal shifting movement whereby the power shifting may not interfere with the operation of the manually operable means. i

` '8. The invention defined by claim 7, said poweroperated means including a transversely moving slide bar, pawls carried thereby, a rocker arm adapted to be rotated by the one or the other of said pawls, connections from said rocker arm to effect longitudinal movements of the high speed shifting element, a lever, means on the slide bar engaging the lever to rock the same, and means whereby the rocking of the lever selects the high speed element for subsequent shifting.

9. In a motor vehicle, a change speed transmission having shift forks, one for high and second speeds and one for low speed and reverse, means movable to lock either one of said forks and to render the other fork operable, said means having a first lever arm, other means to reciprocate the high speed fork, said other means having a second lever arm, power means operable to shift the first arm and thereafter shift the second arm.

10. The invention defined by claim 9 together with a main clutch, mechanism whereby the power-operated means releases the main clutch prior to the operation of the change speed mechanism.

11. In a motor vehicle, an engine, a clutch, change speed mechanism having a plurality of longitudinally movable forks, power-operated means, first means operated thereby to rst lock one fork and release the other for longitudinal movement, and second means also operable by the power-operated means to shift the released fork.

12. The invention defined by claim 11, said first means comprising a transversely movable interlocking plate and a lever member having arms, one engaging the interlocking plate and the other operably connected to the power-operated means.

13. The invention defined by claim 11, said second means comprising a lever having a rst arm to shift said other fork longitudinally, and a second arm operably connected with the poweroperating means.

14. The invention defined by claim 1l, said second means comprising a lever having a first arm to shift said other fork longitudinally, a second arm operably connected with the poweroperating means, said operable connection including a rock arm pivoted to said lever and having terminal pins to be successively engaged by the power-operated means whereby the rock arm and lever are rotated in opposite directions by successive movements of the power-operated means to make progressive shifts between second and third speeds.

15. In a motor vehicle, a change speed transmission having forks shiftable longitudinally, one for Ahigh and second speeds and the other for low and reverse speeds, manually operable means, a mechanism between said manually operable means and said forks whereby the one or the other of said forks is locked and the other fork freed for longitudinal movement and whereby the freed fork may be shifted longitudinally by the manually operable means to make the several shifts. together with power-operated means and other mechanism operated thereby, said other mechanism operable upon said first mentioned mechanism to lock the low 'speed fork and to subsequently shift the other fork.

16. The invention defined by claim 15, said 4power-operated means including mechanism operable to leave the transmission at all times subject to control bythe manually operable means. 17. Control means for the power transmission 10 of a motor vehicle provided with an engine, a

OLAF RAsMUssjEN. xo 

